1. Field of the Invention
This invention relates generally to a catheter to regulate fluid flow through and around the catheter, and more particularly to a catheter which includes at least one antegrade valve coupled to an exterior of the catheter and configured to provide a controlled antegrade flow and a controlled retrograde flow past an exterior of the catheter within the circulatory vessel and/or a catheter which includes at least a retrograde valve coupled to the exterior of the catheter configured to provide a controlled antegrade flow and a controlled retrograde flow.
2. Description of Related Art
Various cardiovascular, neurosurgical, pulmonary and other interventional procedures, including repair or replacement of aortic, mitral and other heart valves, repair of septal defects, pulmonary thrombectomy, coronary artery bypass grafting, angioplasty, atherectomy, treatment of aneurysms, electrophysiological mapping and ablation, and neurovascular procedures, are performed with the patient connected to cardiopulmonary bypass (CPB) equipment to maintain circulation of oxygenated blood throughout the patient's circulatory system. In some of these procedures, such as heart valve replacement and coronary artery bypass grafting, cardiac function is arrested, and peripheral circulation of oxygenated blood is maintained completely by a CPB system. In other procedures, such as angioplasty and atherectomy, the heart remains beating, and CPB is used to assist the heart in maintaining circulation of oxygenated blood during the procedure.
To establish cardiopulmonary bypass according to conventional techniques, a venous cannula is introduced into a major vein such as the inferior vera cava, or into the heart itself to withdraw deoxygenated blood from the patient and deliver the deoxygenated blood to a CPB system for oxygenation. An arterial cannula is introduced into a major artery such as the aorta, an iliac artery, or a femoral artery, for delivering oxygenated blood from the CPB system to the patient's arterial system.
For endovascular procedures such as angioplasty and atherectomy in which cardiac function need not be arrested, interventional devices are introduced into an artery such as a femoral artery, and the devices are transluminally positioned it the treatment site where the procedure is performed. For example, in angioplasty or atherectomy, a catheter is introduced into a femoral artery and advanced through the aorta into a coronary artery to treat an occluded region therein. If CPB is utilized during such procedures, the arterial and venous CPB cannulae are usually introduced into a femoral artery and femoral vein, respectively, by means of a surgical cut-down or over guide wires percutaneously placed in the groin area on one side of a patient's body. Interventional devices may then be introduced into a femoral artery or vein in the groin area on the other side of the patient's body.
In procedures where cardiac function is arrested, on the other hand, the heart and coronary arteries must be isolated from the remainder of the patients arterial system. Using conventional techniques, the sternum is cut longitudinally (a median sternotomy), providing access between opposing halves of the anterior portion of the rib cage to the heart and other thoracic vessels and organs. Alternatively, a lateral thoracotomy is formed, wherein an incision, typically 10 cm to 20 cm in length, is made between two ribs. A portion of one or more ribs may be permanently removed to optimize access. Through this large opening in the chest, a mechanical cross-clamp may be placed externally on the ascending aorta downstream of the ostia of the coronary arteries, but upstream of the brachiocephalic artery, so as to allow oxygenated blood from the CPB system to reach the arms, neck, head, and remainder of the body. A catheter is then introduced through the sternotomy or thoracotomy and inserted into the ascending aorta between the cross-clamp and the aortic valve. Cardioplegic fluid is infused through the catheter into the aortic root and coronary arteries to perfuse the myocardium. An additional catheter may be introduced into t he coronary sinus for retrograde perfusion of the myocardium with cardioplegic fluid. In addition, the myocardium is usually cooled by irrigation with cold saline solution and/or application of ice or cold packs to the myocardial tissue. Cardiac contractions will then cease.
While such open-chest techniques can produce significant benefits for some patients, such techniques entail many days to weeks of hospitalization and months of recuperation time, in addition to the pain and trauma suffered by the patient. Moreover, application of an external cross-clamp to a calcified or atheromatous aorta may cause the release of emboli into the brachycephalic, carotid or subclavian arteries with serious consequences such as strokes.
In response to these problems, new techniques have been developed to facilitate the performance of cardiac procedures such as heart valve repair, coronary artery bypass through a small incision and replacement using endovascular instruments, eliminating the need for a thoracotomy as well as the need for an external aortic cross-clamp. Such procedures are described in U.S. Pat. Nos. 5,584,803 and 5,370,685 incorporated herein by reference. Similarly, in U.S. Pat. No. 5,452,733 the complete disclosure of which is incorporated herein by reference, methods and devices are described for performing coronary artery bypass grafting and other procedures through small incisions or cannulae positioned through the chest wall, obviating the need for a thoracotomy. This new generation of minimally-invasive cardiac procedures provides significant advantages over conventional open surgical techniques, including reduced mortality and morbidity, decreased patient suffering, reduced hospitalization and recovery time, and lowered medical costs relative to open-chest procedures.
These new generation minimally-invasive cardiac procedures and devices use balloons to isolate vessels and different sections of the heart. These balloons require large fluid inflation lumens in the catheter, thereby dimensioning respective effective inner diameters or requiring larger catheters. When the balloon is large the wall tensions of the balloon are increased and there is a significant chance of balloon rupture. Balloons may disrupt interior lesions of vessels. Additionally, balloons serve as total roadblocks to the passage of fluids, including but not limited to blood.
It would be desirable to provide a catheter configured to access a vein, artery, a great artery or a heart chamber, which uses valves instead of balloons and minimize the problems associated with balloons. To regulate flow around the catheter it would be further desirable to provide a catheter with exterior antegrade valves that provide antegrade flow past the antegrade valve and a controllable retrograde flow past the antegrade valve. It would be even further desirable to provide exterior retrograde valves that provide retrograde flow past the retrograde valve and a controllable antegrade flow past the retrograde valve.